Effect of temporal decorrelation on forest height inversion using repeat pass TerraSAR-X data

The estimation of forest height in X-band using Random-Volume-over-Ground model has been demonstrated successfully several times using long wavelength airborne Pol-InSAR data. TerraSAR-X provides for the first time interferometric X-band data from space in a repeat pass mode. However, X-band is highly affected by temporal decorrelation (11 days of temporal baseline). Additionally, the available spatial baselines are formed by chance; therefore sensitivity to forest height changes between the interferometric pairs. In this study 6 interferometric X-band acquisitions were investigated. For data quality estimation interferometric coherence was calculated. Decorrelation sources have been identified and evaluated. The main factor affecting interferometric coherence is temporal decorrelation. For an outlook an optimum acquisition scenario, excluding temporal decorrelation was derived for a single pass acquisition.